We have an established process for a product that is protected with a Tyvek®/Film pouch. We are performing a large destructive post-sterile inspection after EtO sterilization (burst/creep test, we also perform this test on pre-sterile stage). The
specification developed many years ago has a value for creep and burst that was developed for pre-sterile material.
I just found out that the post-sterile testing does not always meet this spec and that as long as they see a minimum seal area when the seal test fails, they would accept the lot.
I’ve been trying to find the rationale as to how the limits for the current spec were established and want to get rid of the destructive testing on the post-sterile stage.
Where can I start to determine my acceptance criteria for post-sterile inspection and can I validate the sterilization effect on the final product and stop performing costly and time consuming post-sterile testing? Any help is greatly appreciated.
Before discussing the rationale for this change there are a few questions that you may have
already addressed but are still ones that must be noted here. If there is a consistent trend that
data shows a drop in seal strength from pre- to post- EtO sterilization, it is an indicator that
something is occurring that may be unexpected and worthy of investigation.
Rationale for Current Specification:
Three established test procedures define methods for determining Burst and Creep test criteria,
and minimum specification values. Please review the following methods to determine if your
current criteria are in alignment with these standards:
Once you have established that your test criterion meets the requirements of these standards, we
can address your post-sterile inspection question.
Since this appears to be an established practice that has been in place for a number of years, you
probably have enough statistical evidence to prove that if your packaging has met the required
pre-sterile test criteria, your seals, and the minimum specification is sufficient for the sterilization process and distribution. You may want to begin by compiling a significant amount of your pre-sterile test results. This should be a minimum of 30 values, and cover a minimum of 3 lots. The more data that you can compile will provide additional support for your rationale for suspending post-sterile inspection.
Next step would be to correlate your pre-sterile results with the post-sterile results. These results
should be examined over the same lots/time period you chose to compile for the pre-sterile analysis. Even if you had failing post-sterile burst/creep test data, (and the default criteria for release was a minimum seal width), it still supports your rationale – if these packages were released to the field, and no sterilization failures occurred in the field.
Of key importance is tying together these three pieces of information in order to create a rationale for the change you propose. The appropriate review and approvals would follow in accordance with your corporate change policy.